The actors were also joined by Edward Norton and Joe Jonas who turned up for the famed Italian brand's store opening and its new designer Stefano Pilati.

Thursday night in Beverly Hills was the occasion of the long-awaited new Zegna boutique's opening at 337 North Rodeo, designed by famed architect Peter Marino. Its original location of eighteen years is now being rebuilt as the new home of Burberry. Zegna, of course, is the famed Italian brand known for making the most luxurious mens' suits, sweaters, shirts and accessories.

Cocktails were served in the new store to welcome Zegna's new designer Stefano Pilati -- formerly the designer of womenswear at YSL -- and Zegna CEO Gildo Zegna. And there was no shortage of A-list male celebs turning up in their amazing new Zegna finery: Edward Norton, Jeremy Renner and Joe Jonas toasted the designer and the Zegna family, then headed to the JF Chen large gallery space at 941 North Highland, where even more A-listers turned up including Sharon Stone, Gerard Butler, Gavin Rossdale, Joe Manganiello, Jim Parsons, Ethan Peck, Nathan Keyes, George Kotsiopoulos, Cameron Silver and stylist Brad Goreski, among them.

The Chen space was downstairs outfitted with very large photos of the Zegna spring 2014 ad campaign (with clothes designed by Pilati) starring British actor Jamie Dornan -- good timing on Zegna's part as he was just announced as playing the lead Christian Grey in Fifty Shades of Grey -- and video of cultural influences on the spring collection.

Upstairs the enormous space was filled with beautifully dressed people -- many speaking Italian -- and gorgeous catered food by Lucques. We've rarely seen such beautiful food at a party -- no wonder everyone seemed to have a plate in front of them despite their expensive suits and dresses. Goreski is thrilled with the new clean modern direction of Zegna: "It's all so beautiful, and crazy expensive: a suit is about seven thousand dollars! There's one cashmere jacket that's five thousand that is also crazy - but I think I have to buy it anyway."

Jonas, in a brown-toned suit with a pink Zegna dress shirt, admitted, "Zegna made this suit for me. That's why it fits so incredibly well. I'm not normally a suit guy, but if you're going to wear a suit, it makes sense to wear the best one there is."

Butler is also a fan of the Italian label. "I love Zegna because I love suits – and I have many of them. I'm a guy who feels comfortable in a suit," said the Olympus Has Fallen actor. "And I love this Zegna blue suit with a blue shirt and tie. I'm seriously blue tonight, even though I'm in a great mood!"

It looked like the buzzing group of ladies around him liked it a lot, too.